The present invention relates to a conveyance chain particularly for providing industrial handling mechanisms, such as for example conveyor belts.
Conveyance chains are currently used which comprise a plurality of mutually identical links arranged sequentially on a plane so as to form an axis of motion for said chain.
Each link is associated with the next by way of a mechanism based on universal joints which allows not only to drive the various links but also allows their mutual rotation with respect to two axes that are preferably perpendicular to each other and to said axis of motion.
In this regard, Italian patent No. 1,152,656 is known which discloses a conveyance chain provided with links that comprise a main part, or head, from which two stems protrude at the rear so as to surround the head of the next link.
A first cylindrical hole is formed in the head along an axis that is generally perpendicular to the direction of motion and forms a seat in which a cylindrical element constituted by a rotating bush is rotatably associable.
A pivot can be arranged in a second hole provided transversely to the bush along an axis that is approximately perpendicular to the axis of motion and is designed to allow the pivoting of the two contiguous links: said pivot is therefore engaged between the head of one link, which can be referenced as rear link, and the stems of a contiguous link, which can be referenced as front link.
Two sleeves protrude externally to said stems of the front link and surround and accommodate the ends of the pivot.
The main drawback of said known type of conveyance chain is that it is constituted by three separate components, and this increases the work needed to assemble said chain, whose length can be even considerable: each link must in fact be associated with the next by interposing two other components.
Another drawback of these known types is constituted by the cost for producing these components.
Further, the transverse pivot is usually made of steel: accordingly, there is the drawback of having not only a high purchase cost for said pivot but also a high weight of the conveyance chain.
This entails disadvantages both of the structural type and of the energy-related type, since there is a greater expenditure of energy to move the chain.
Another important drawback is that disposing of the conveyance chain at the end of the period of useful life is very complicated to perform.
Further, the steel pivot must be inserted by interference coupling, and this entails a very laborious and difficult operation, with possible generation of rejects.